On Mar 31, 12:36?pm, "David Eduardo" wrote:
wrote in message

oups.com...

"What they are not telling you about HD Radio"

http://groups.google.com/group/ba.br...ad/thread/4699...

Oh great - the HD Radio Alliance can track what is listened to - need
to get this one to the press ASAP !

Yeah, right. An HD radio has no transmit capabilities, and you know it.

How do you know - it doesn't really matter, because word is spreading,
and I'll make sure it does !

wrote in message
oups.com...
On Mar 31, 12:36?pm, "David Eduardo" wrote:
wrote in message

oups.com...

"What they are not telling you about HD Radio"

http://groups.google.com/group/ba.br...ad/thread/4699...

Oh great - the HD Radio Alliance can track what is listened to - need
to get this one to the press ASAP !

Yeah, right. An HD radio has no transmit capabilities, and you know it.

How do you know -

Very simple... it doesn't transmit.

..

On Mar 31, 12:36?pm, "David Eduardo" wrote:
wrote in message
..

Oh great - the HD Radio Alliance can track what is listened to - need
to get this one to the press ASAP !

Yeah, right. An HD radio has no transmit capabilities, and you know it.

How do you know -

Very simple... it doesn't transmit.
"""""""""""""""""""""""""""""""""""""""""""""""""" """"""""""""""""""""""""""""

Every superhetrodyne transmits a signal via its oscillator.
Example 1.
In WWII Nazi submarines used TRF receivers as the oscillator in a
superhet put out enough signal that air and naval sub chasers could
home in on the signal and deep-six them.

Example 2
In 1985, my auto Radar detector, the latest in Stealth technology,
was detected by a police cruiser using even later detector technology.
"Oh sure," chuckled the cop as he wrote out a ticket," I heard you
right across the valley."

Example 3.
My old diode detector radar detector was invisible to the police
detectors.

Therefore, when buying a new iboc radio, tell the clerk that you
insist on a TRF model that will ensure your privacy. Wearing your
tinfoil hat might help get his attention. I am sure that small-signal
reception techniques have improved since 1944.

On 31 Mar 2007 11:02:47 -0700, "ve3..." wrote:


In WWII Nazi submarines used TRF receivers as the oscillator in a
superhet put out enough signal that air and naval sub chasers could
home in on the signal and deep-six them.

?

"David" wrote in message
...
On 31 Mar 2007 11:02:47 -0700, "ve3..." wrote:


In WWII Nazi submarines used TRF receivers as the oscillator in a
superhet put out enough signal that air and naval sub chasers could
home in on the signal and deep-six them.

In fact, there is a ratings service, called MobilTrak which installs
antennas on utility poles where cars go by, and can tell what FM station is
being listened to based on the IF offset, but it does not work on AM.

http://www.mobiltrak.com/ has an explanation of the technology.

Mostly, this is used by retail business to see what station is listened to
at point of purchase (POP) for ad effectiveness studies. It is of limited
value in quantifying audience, as 2/3 of radio listening is not in the car.

On Sat, 31 Mar 2007 20:47:23 GMT, "David Eduardo"
wrote:


"David" wrote in message
.. .
On 31 Mar 2007 11:02:47 -0700, "ve3..." wrote:


In WWII Nazi submarines used TRF receivers as the oscillator in a
superhet put out enough signal that air and naval sub chasers could
home in on the signal and deep-six them.
Except that TRF receivers have no oscillators. The reason the military
like TRF radio's is absent any oscillator, they don't emit anything to
give away position or frequency....



In fact, there is a ratings service, called MobilTrak which installs
antennas on utility poles where cars go by, and can tell what FM station is
being listened to based on the IF offset, but it does not work on AM.
Works only until someone decides to build an FM receiver with an IF
somewhere other than 10.7 Mhz....

http://www.mobiltrak.com/ has an explanation of the technology.

Mostly, this is used by retail business to see what station is listened to
at point of purchase (POP) for ad effectiveness studies. It is of limited
value in quantifying audience, as 2/3 of radio listening is not in the car.

On Sun, 01 Apr 2007 20:21:15 GMT, matt weber
wrote:


Works only until someone decides to build an FM receiver with an IF
somewhere other than 10.7 Mhz....


http://www.gnu.org/software/gnuradio...ck-diagram-fig

On Sat, 31 Mar 2007 20:41:13 GMT, David wrote:

On 31 Mar 2007 11:02:47 -0700, "ve3..." wrote:


In WWII Nazi submarines used TRF receivers as the oscillator in a
superhet put out enough signal that air and naval sub chasers could
home in on the signal and deep-six them.

?

I get it. You forgot a comma.